Search

Your search keyword '"Men, Yongjun"' showing total 48 results
Start Over Author "Men, Yongjun"
48 results on '"Men, Yongjun"'

4. Review of Shape Transformation Pathways of Polymersomes: Implications for Nanomotor, Biomedicine, and Artificial Cell Mimics.

Author

Zhang, Xurui, van Hest, Jan C. M., and Men, Yongjun

Abstract

Polymersomes have been studied for many years since their discovery, and have consistently been an appealing and widely explored research domain. Their inherent benefits, encompassing stability, versatility, load-carrying capacity, and deformability, endow them with many opportunities to be used in numerous fields of biomedicine, nanocarriers, diagnostics and therapeutics. Nevertheless, shape transformation pathways have not been comprehensively summarized or received adequate scholarly attention. Herein, we summarize typical mechanisms underlying polymersome self-assembly with a particular focus on the shape transformation pathways associated with commonly employed self-assembling methods. Moreover, we provide a succinct overview of the proposed applications involving shape transformation applications, and enumerate the most recent findings in this domain. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

16. A Fuel‐Driven Chemical Reaction Network Based on Conjugate Addition and Elimination Chemistry.

Author

Fan, Bowen, Men, Yongjun, Rossum, Susan A. P., Li, Guotai, and Eelkema, Rienk

Subjects
*CHEMICAL reactions, *CONJUGATE addition reactions, *CHEMICAL systems, *COVALENT bonds, *BOND formation mechanism
Abstract

Fuel‐driven chemical reaction networks provide an opportunity to develop chemical systems that operate out‐of‐equilibrium. There remains a need to design and develop new fuel‐driven chemical reaction networks capable of repeated operation using simple and benign chemistry. Herein, we propose a new chemical reaction network for fuel‐driven transient formation of covalent bonds, based on redox‐controlled conjugate addition and elimination chemistry. By investigating the separate reactions making up the cycle, we find that the bond formation, breaking and regeneration processes can be realized. At present, substantial side reactivity prevents achieving repeated operation of a full cycle in a single system. If such obstacles would be overcome, this chemical reaction network could be a valuable addition to the toolbox for out‐of‐equilibrium systems chemistry. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

24. Tailoring Polymersome Shape Using the Hofmeister Effect

Author

Men, Yongjun, Li, Wei, Lebleu, Coralie, Sun, Jiawei, and Wilson, Daniela A.

Abstract

Reshaping polymersomes remains a challenge for both size and shape control, methodology development, and mechanism understanding, which hindered their application in nanomedicine and nanomachine. Unlike liposome, polymersomes are capable of maintaining their shape due to their rigid and glassy membrane. Here we use the Hofmeister effect to guide the shape control of polymersome by tuning the ion type and concentration. Multiple morphologies such as ellipsoid, tube, disc, stomatocytes, and large compound vesicles are found. These results give evidence of demonstrating that the shape changes are not only induced by osmotic pressure, but also by the interaction with the polymersome membranes. Additionally, this methodology provides a general tool to tailor the shape of polymersome into various morphologies.

Published
2020
Full Text
View/download PDF

25. Nonequilibrium Reshaping of Polymersomes viaPolymer Addition

Author

Men, Yongjun, Li, Wei, Tu, Yingfeng, Peng, Fei, Janssen, Geert-Jan A., Nolte, Roeland J. M., and Wilson, Daniela A.

Abstract

Polymersomes are a class of artificial liposomes, assembled from amphiphilic synthetic block copolymers, holding great promise toward applications in nanomedicine. The diversity in polymersome morphological shapes and, in particular, the precise control of these shapes, which is an important aspect in drug delivery studies, remains a great challenge. This is due to a lack of general methodologies that can be applied and the inability to capture the morphologies at the nanometer scale. Here, we present a methodology that can accurately control the shape of polymersomes viathe addition of polyethylene glycol (PEG) under nonequilibrium conditions. Various shapes including spheres, ellipsoids, tubes, discs, stomatocytes, nests, stomatocyte-in-stomatocytes, disc-in-discs, and large compound vesicles (LCVs) can be uniformly captured by adjusting the water content and the PEG concentration. Moreover, these shapes undergo nonequilibrium changes in time, which is reflected in their phase diagram changes. This research provides a universal tool to fabricate all shapes of polymersomes by controlling three variables: water content, PEG concentration, and time. The use of the biofriendly polymer PEG enables the application of this methodology in the field of nanomedicine.

Published
2019
Full Text
View/download PDF

44. Self-propelled supramolecular nanomotors with temperature-responsive speed regulation

Author

Tu, Yingfeng, Peng, Fei, Sui, Xiaofeng, Men, Yongjun, White, Paul B., van Hest, Jan C. M., and Wilson, Daniela A.

Abstract

Self-propelled catalytic micro- and nanomotors have been the subject of intense study over the past few years, but it remains a continuing challenge to build in an effective speed-regulation mechanism. Movement of these motors is generally fully dependent on the concentration of accessible fuel, with propulsive movement only ceasing when the fuel consumption is complete. Here we report a demonstration of control over the movement of self-assembled stomatocyte nanomotors via a molecularly built, stimulus-responsive regulatory mechanism. A temperature-sensitive polymer brush is chemically grown onto the nanomotor, whereby the opening of the stomatocytes is enlarged or narrowed on temperature change, which thus controls the access of hydrogen peroxide fuel and, in turn, regulates movement. To the best of our knowledge, this represents the first nanosized chemically driven motor for which motion can be reversibly controlled by a thermally responsive valve/brake. We envision that such artificial responsive nanosystems could have potential applications in controllable cargo transportation.

Published
2017
Full Text
View/download PDF

47. Engineering Rapeseed Germination and Root Growth with Mechanical Strength of Polysaccharide Hydrogel.

Author

Wu Q, Xie J, Li J, Men Y, and Yan F

Subjects
Brassica rapa growth & development, Brassica rapa chemistry, Particle Size, Biocompatible Materials chemistry, Hydrogels chemistry, Plant Roots growth & development, Polysaccharides chemistry, Materials Testing, Germination
Abstract

Plant roots are highly sensitive to physical stress in the soil, with appropriate mechanical impedance promoting root elongation and lateral root growth. However, few studies have quantitatively explored the relationship between the mechanical impedance of the growth medium and the phenotypes of plant roots. In this study, we used a tensile machine equipped with a self-made steel needle mimicking the root tip to measure the force needed to penetrate the hydrogel medium (agar, low acyl gellan gum, and κ-carrageenan), providing insights into the force required for the rapeseed root tip to enter the medium following germination. These findings indicate that root penetration length is inversely associated with the mechanical strength of the growth medium, with variations observed in the root system adaptability across different substrates. Specifically, when the gel puncture resistance of the culture medium without adding MS reached approximately 18.4 mN, root penetration and growth were significantly hindered. With the addition of 1/2 MS medium, the polysaccharide concentration is 1.0 wt %, which is more suitable for cultivating rapeseed. This research not only offers a method for quantifying root phenotypes and medium mechanical impedance but also presents an approach for plant growth regulation and crop breeding.

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results